Updates of the cdimage.d.o webpages

[Othmar Pasteka <pasteka@kabsi.at>]

hi,

i just looked at cdimage.d.o about the _CDa images if there is a
statement on this but couldn't find any. it just says that
2.2_rev0 are the official ones, so the _CDa aren't (if a new user
reads that). afaik is _CDa also an official image. maybe one
should update the pages on these kind of images and also give a
short explanation why there is _CDa. 

so logn
Othmar